In: Physics
5) Two point charges of +20.0 μC and -8.00 μC are separated by a distance of 20.0 cm. What is the intensity of electric field E midway between these two charges?
a. 25.2 × 105 N/C directed towards the positive charge
b. 25.2 × 106N/C directed towards the positive charge
c. 25.2 × 104 N/C directed towards the negative charge
d. 25.2 × 105 N/C directed towards the negative charge
e. 25.2 × 106 N/C directed towards the negative charge
The electric intensity at the mid point is equal to thealgebraic
sum of the intensities due to individual charges.
i.e., E= E1 + E2 =
k(q1 +
q2)/r2 where k
= (1/4πε) = 8 * 10^9 for freespace.
andsince
the distance from the two points is same.
Hence
E = 8 * 10^9 ( 20 + 8 ) * 10^-6 / (10 *10^-2)2
On simplifying
weget, E = 3.51 * 10^7N/c
Hope this helps you.